Endogenous polyamine concentrations during development, storage and ripening of pear fruits
1988; Elsevier BV; Volume: 27; Issue: 2 Linguagem: Inglês
10.1016/0031-9422(88)83092-9
ISSN1873-3700
AutoresArazdordi Toumadje, Daryl G. Richardson,
Tópico(s)Plant Surface Properties and Treatments
ResumoBartlett and Comice pears both had about 270 nmol/g of putrescine (PUT) one month after full bloom (AFB) and decreased to a low level at harvest. However, at early stages of fruit development Comice pears contained more than twice as much spermidine (SPD) as did Bartlett pears. The spermine (SPM) was undetectable at early development in Bartlett pears but was 244 nmol/g in Comice pears. Polyamine concentrations were also determined during storage of D'Anjou pears at −1° for 74 days. SPD was the polyamine in highest concentration and SPM the lowest, early in storage; the latter decreased to undetectable levels after 60 days in storage. After 40 days at −1° polyamines decreased to about 3 nmol/g and this corresponded to the time when ethylene synthesis began. Anjou pears which had not fulfilled their chilling requirements were not able to ripen or synthesize ethylene when held 14 days at 20°. In these tissues, PUT and SPD decreased but SPM did not change in concentration significantly during 14 days at 20°. In ‘Packham's Triumph’ pears that had been chilled at −1° to produce ethylene and ripen normally on transfer to 20°, the SPM decreased to an undetectable level by day four of ripening. There were no significant changes in PUT concentration, but SPD decreased gradually during ripening. It appears that SPM may play some regulatory role in ethylene metabolism, but the role of PUT and SPD is less clear.
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